Speaking at a graduation ceremony for Israeli Navy cadets last Wednesday, Netanyahu accused Iran of smuggling petroleum products to bypass U.S. sanctions. He anticipated a “more important role” for the Israeli Navy in “efforts to block these Iranian actions” and hinted some of Israel’s operations would be covert in nature.

“I call on the international community to halt, by any means, Iran’s attempts to bypass the sanctions via the sea,” Netanyahu added.

A week later, the Iranian defense minister responded that Iran “enjoys the required capability to respond to this issue and if it happens, it will give a crushing response.”

Hatami interpreted Netanyahu’s comments as a threat to engage in “international piracy” and vowed Iranian forces will “secure the security of shipping lines and international shipping lanes for ourselves and all those who are in our area of responsibility.”

The latter qualification is important because Iran constantly threatens actual piracy against ships passing through the Strait of Hormuz, effectively presenting a blockade of the strategically vital strait as a trump card Tehran will play if the pressure of American sanctions becomes too great. Iran can hardly pretend to be a defender of free navigation for everyone.

Iran has expanded its naval operations over the past few years, including missions to the Indian Ocean and Gulf of Aden, where the Iranian navy claims to have repelled a bona fide pirate attack last week. As reported by Iran’s state-controlled media, an Iranian oil tanker was attacked last Thursday by a swarm of 11 pirate speedboats, who were driven off by Iranian Navy commandos.

Reutersreported on Wednesday that Iran’s oil tanker fleet is aging and U.S. sanctions are making it difficult for Tehran to maintain or replace the ships.

Iran’s bid to buy ten new supertankers from South Korea stalled out after the United States pulled out of the nuclear deal and re-imposed sanctions, while the Greek network that previously helped Tehran buy new ships has been blacklisted. Insurance companies have become reluctant to write policies for Iranian vessels.

“Iran has been looking for ships, but this time round it is going to be harder – there is so much more scrutiny now. It is going to take them longer,” a source within the shipping industry told Reuters.